The final principle of extension doubles back on itself with a self-referential observation. What kind of creatures are we? The kind who extend, eagerly and energetically, when given the chance. Consider: research from neuroscience and cognitive psychology indicates that when we begin using a tool, our “body schema”—our sense of the body’s shape, size, and position—rapidly expands to encompass it, as if the tool we’re grasping in our hand has effectively become an extension of our arm.
